shutdown

NAME

SYNOPSIS

DESCRIPTION

shutdown
arranges for the system to be brought down in a safe way. All logged-in
users are notified that the system is going down and, within the last
five minutes of
TIME,
new logins are prevented.

TIME
may have different formats, the most common is simply the word
'now'
which will bring the system down immediately. Other valid formats are
+m,
where
m
is the number of minutes to wait until shutting down and
hh:mm
which specifies the time on the 24hr clock.

Once
TIME
has elapsed,
shutdown
sends a request to the
init(8)
daemon to bring the system down into the appropriate runlevel.

This is performed by emitting the
runlevel(7)
event, which includes the new runlevel in the
RUNLEVEL
environment variable as well as the previous runlevel (obtained from the
environment or from
/var/run/utmp)
in the
PREVLEVEL
variable. An additional
INIT_HALT
variable may be set, this will contain the value
HALT
when bringing the system down for halt and
POWEROFF
when bringing the system down for power off.

OPTIONS

-r

Requests that the system be rebooted after it has been brought down.

-h

Requests that the system be either halted or powered off after it has been
brought down, with the choice as to which left up to the system.

-H

Requests that the system be halted after it has been brought down.

-P

Requests that the system be powered off after it has been brought down.

-c

Cancels a running shutdown.
TIME
is not specified with this option, the first argument is
MESSAGE.

-k

Only send out the warning messages and disable logins, do not actually
bring the system down.

ENVIRONMENT

RUNLEVEL

shutdown
will read the current runlevel from this environment variable if set in
preference to reading from
/var/run/utmp

FILES

/var/run/utmp

Where the current runlevel will be read from; this file will also be updated
with the new runlevel.

/var/log/wtmp

A new runlevel record will be appended to this file for the new runlevel.

NOTES

The Upstart
init(8)
daemon does not keep track of runlevels itself, instead they are implemented
entirely by its userspace tools.